Exercise device



FIG. 1 is a perspective view of an exercise device of the claimed design;

FIG. 2 is a front view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a bottom view thereof;

FIG. 5 is a side view thereof; and,

FIG. 6 is a rear view thereof.

The broken line portions of the figure drawings are included to show unclaimed subject matter only and form no part of the claimed design. 

The ornamental design for an exercise device, as shown and described. 